Abstract: A fastening system having a continuously curved countersink section in an aperture through a plurality of workpieces, with a corresponding rivet having a continuously curved head portion substantially congruent to the continuously curved countersink. Rivets equipped with the continuously curved head surfaces taught herein, when mated with a continuously curved countersink, provide sufficient resistance to fastener pull through, cause cold working of the rivet upon insertion of the rivet into the aperture and impose an elastic load upon the workpiece and rivet, strengthening the joint.

Abstract: A fastening system having a continuously curved countersink section in an aperture through a plurality of workpieces, with a corresponding rivet having a continuously curved head portion substantially congruent to the continuously curved countersink. Rivets equipped with the continuously curved head surfaces taught herein, when mated with a continuously curved countersink, provide sufficient resistance to fastener pull through, cause cold working of the rivet upon insertion of the rivet into the aperture and impose an elastic load upon the workpiece and rivet, strengthening the joint.

Abstract: A pin fastening device having a double tapered head, the angle of one taper being on the order of 80 degrees, or sufficient to withstand severe longitudinal forces, and the angle of the other taper being on the order of 10 degrees, so as to provide a substantial interference fit between the pin and the work members. This double tapered head may be effectively utilized with a wide variety of pin fastener attachment end styles. Furthermore, an attachment end of a pin fastener is disclosed which includes a novel configuration of annular rings, which rings have a thread angle of 60 degrees, and relatively small radii of curvature at their trough and peak. By having such a set of annular rings, one portion of the pin may be longitudinally extended sufficiently to give the pin large shear force resistance, while sufficient total ring surface is retained to withstand large tension forces. A single pin may thus have both a high shear and tension resisting capacity.

Abstract: A high fatigue slug squeeze riveting process using two clamps, one of which is a fixed position clamp, and an apparatus for carrying out the process is disclosed. A pair of panels or other items to be riveted together are clamped by upper and lower clamps and a hole is drilled through the items. Thereafter, a nonheaded rivet slug is inserted in the hole. After insertion of the slug, upper and lower rams approach the rivet along vertical, axially aligned paths. The upper ram is flanked by a pair of spring-loaded rods, known as pogo feet, which extend past the impinging face of the ram. The lower ram stops at a predetermined position, providing a positioning stop for the rivet slug. The upper ram continues down. Since the pogo feet extend past the impinging face of the upper ram, they contact the adjacent surface of the items to be riveted prior to the upper ram contacting the rivet slug.

Abstract: A rigid and an axially movable tool for squeeze forming a rivet, each having a facing resilient member to contact a part to be riveted, to center the rivet between the clamping tools, and to float the part to be riveted to symmetrically form the rivet.

Abstract: A fastening system having a continuously curved countersink section in an aperture through a plurality of workpieces, with a corresponding pin-fastener having a continuously curved head portion substantially congruent to the continuously curved countersink. Pin fasteners and bolts equipped with the continuously curved head surfaces taught herein when mated with a continuously curved countersink provide sufficient resistance to fastener pull through, cause cold working of the workpiece around the countersink, and impose an elastic load upon the workpiece and fastening strengthing the joint.

Abstract: A pin fastening device having a double tapered head, the angle of one taper being on the order of 80.degree., or sufficient to withstand severe longitudinal forces, and the angle of the other taper being on the order of 10.degree., so as to provide a substantial interference fit between the pin and the work members. This double tapered head may be effectively utilized with a wide variety of pin fastener attachment end styles. Furthermore, an attachment end of a pin fastener is disclosed which includes a novel configuration of annular rings, which rings have a thread angle of 60.degree., and relatively small radii of curvature at their trough and peak. By having such a set of annular rings, one portion of the pin may be longitudinally extended sufficiently to give the pin large shear force resistance, while sufficient total ring surface is retained to withstand large tension forces. A single pin may thus have both a high shear and tension resisting capacity.